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    <script>
        var arr = [1,9,0,8,5,3,0,2,0,2,4,9]
        var newArr = [];
    
        for(var i = arr.length-1; i >= 0; i--){
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            // i初始化为旧数组的长度-1，因为数组索引从零开始
            // 当i大于等于0，结束循环
            // 每次循环i减1
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        console.log(arr);
        console.log(newArr);
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